Electrical connector and insulation-piercing contact member

ABSTRACT

An electrical connector comprising two dielectric contact mounts, one a plug and the other a receptacle, fitting together to engage a plurality of conductive contact members carried by one contact mount with similar contact members mounted in the other. Each contact member is formed from a single piece of thin, conductive sheet metal, with a contact element at one end and a terminal element at the other; the terminal element is channel-shaped with two terminal flanges each struck from a channel wall and bent across the channel, preferably into interlocking relation with another channel wall. Each terminal flange has a notch with thin converging walls affording a cutting section to cut the insulation on a conductor inserted into the notch, a transition section with tapered walls to spread the insulation, and a terminal section with thick, smooth walls to engage the conductor in wiping electrical contact. The contact mounts include resilient retention slots for holding the electrical conductors in the terminal elements of the contact members.

BACKGROUND OF THE INVENTION

In multi-circuit electrical connectors, of the kind used in greatvariety and numbers in communication systems and other data handlingsystems, the usual technique for connecting the individual solid orstranded wire conductors to the connector has been to strip theinsulation from the end of the conductor and then solder the conductorto a connector contact. This procedure requires considerable skill onthe part of the workman making the solder connection, particularly inminiaturized connectors. There is also a tendency to bridge adjacentcontacts of the connector, during the soldering operation, producingundesired circuit connections.

The conventional soldered connection has long been recognized asrequiring improvement or replacement. One alternative, gainingincreasing acceptance, entails the use of insulation-piercing terminalsfor the contact members of the connector; these terminals cut throughthe insulation and establish an electrical connection to the conductorwithout preliminary stripping and without the conventional solderingstep. The insulation-piercing terminals are usually of forkedconstruction, with cutting edges that penetrate the wire insulation andthat also serve as contact jaws that make the necessary electricalconnection with the conductor. That is, a forked terminal element on theconnector contact serves both as an insulation cutting device and as anelectrical contact.

These forked insulation-cutting contacts have a number of disadvantages.Because the contact jaws must be sharp enough to pierce and penetratethe insulation, there is a substantial tendency to cut into theconductor, particularly the individual fragile members of a strandedwire conductor, thereby, weakening the conductor and sometimesdisrupting current flow, by disturbance of the skin effect, in highfrequency applications. In cutting contact jaws of this kind, the jawsdo not open up to the size of the conductor diameter and do not apply anevenly distributed surface pressure to the conductor. Instead, the jawspacing remains relatively constant, emphasizing scoring of theconductor which may lead to a broken conductor if the connector issubject to vibration in use, and failing to provide the sliding frictionbetween the conductor and the contact jaws that affords optimumelectrical contact. The scored part of the conductor is particularlysusceptible to corrosion. Moreover, the usual forms of forkedinsulation-piercing contacts do not provide positive means for keepingthe conductors in place, but require separate retainers.

SUMMARY OF THE INVENTION

It is a principal object of the present invention, therefore, to providea new and improved unitary contact member that incorporates a terminalstructure which permits direct insulation-piercing connection to anelectrical conductor without engendering the difficulties anddisadvantages of previously known devices of this general kind.

A particular object of the invention is to provide a new and improvedinsulation-piercing terminal element, formed as a part of a unitarysheet metal contact member for an electrical connector, that does notcut into the electrical conductor to an appreciable extent when aconnection is made.

Another object of the invention is to provide a new and improved unitarycontact member for an electrical connector, formed from a single pieceof thin, conductive sheet metal, that effectively pierces and penetratesthe insulation on a conductor and that also provides a sliding frictioncontact, in engaging the conductor, once the insulation has beenpenetrated.

Another object of the invention is to provide a new and improvedinsulation-piercing terminal element for an electrical connector contactmember of the kind constructed from a single piece of thin conductivesheet metal that is inherently strong and rugged and capable ofwithstanding several insertions and removals of an electrical conductorin changing connections to the contact member.

A further object of the invention is to provide a new and improvedelectrical connector, of the kind using individual sheet metal contactsmounted in mating dielectric contact mounts, that affords effectiveretaining means for holding individual electrical conductors inengagement with insulation-piercing terminal elements formed integrallywith the contact members.

A specific object of the invention is to provide a new and improvedunitary sheet metal contact member for a multi-circuit electricalconnector that is inherently simple and inexpensive in construction, yetprovides for optimum electrical qualities and mechanical qualities inthe completion of solderless electrical terminal connections.

Accordingly, the invention relates to a unitary contact member, formedfrom a single piece of thin, conductive sheet metal, for an electricalconnector of the kind comprising a first dielectric contact mount and asecond dielectric contact mount each having a plurality of contactmounting passages, the two contact mounts fitting together to align theinner ends of the contact passages in the first mount one-for-one withthe inner ends of the contact passages in the second mount. The contactmember comprises an active contact element, positioned in the inner endof a given passage in one mount, for engaging a mating active contactelement positioned in the inner end of the aligned passage in the othermount. The contact member further comprises an integral terminalelement, comprising an elongated channel of U-shaped cross-sectionalconfiguration, positioned in the outer end of the passage. The terminalelement includes at least one terminal flange struck from a wall of thechannel and bent inwardly to extend transversely of the channel, theflange having an upwardly opening notch for receiving aninsulation-covered electrical conductor. The upper portion of the notchhas thin edges which converge downwardly to afford a cutting section forshearing through the insulation on the conductor. The medial portion ofthe notch has gradually thickened edges constituting a transitionsection for spreading the insulation on the conductor. The lower portionof the notch has smooth, thick edges free of cutting edges and generallycurved affording a pressure jaw terminal section engaging the electricalconductor in wiping contact.

An electrical connector for interconnecting a plurality of electricalcircuits, in accordance with the invention, comprises a first contactmount and a second contact mount, each formed of molded dielectricmaterial and each having a plurality of contact mounting passagesextending therethrough; the two contact mounts fit together to align theinner ends of the contact passages in the first mount one-for-one withthe inner ends of the contact passages in the second mount. The outerend of each contact passage is of elongated U-shaped configuration. Aplurality of unitary contact members, each formed from a single piece ofthin, conductive sheet metal, are included in the connector, one contactmember mounted in each contact passage. Each contact member includes anactive contact element positioned in the inner end of the contactpassage and an integral terminal element disposed within the outer endof the contact passage. The terminal element of each contact membercomprises an elongated channel smaller in width than the width of theouter end of the contact passage and includes at least one terminalflange extending transversely of the channel and having aninsulation-piercing notch for receiving an insulation-covered electricalconductor and completing an electrical connection between the conductorand the contact member. Resilient retention means, molded integrallywith each contact mount, are provided for releasably retaining theindividual electrical conductors in the terminal elements of the contactmembers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the plug member of an electrical connectorconstructed in accordance with the present invention;

FIG. 2 is a side elevation view of the plug member illustrated in FIG.1;

FIG. 3 is a side elevation view of a receptacle member for an electricalconnector constructed in accordance with the present invention;

FIG. 4 is a bottom view of the receptacle member illustrated in FIG. 3;

FIG. 5 is a transverse sectional view, on an enlarged scale, of the plugand receptacle members of FIGS. 2 and 3, aligned for joining withexternal wire connections;

FIG. 6 is a side elevation view, drawn to a much larger scale thanpreceding figures, of the terminal element of a contact memberconstructed in accordance with one embodiment of the invention;

FIG. 7 is a front elevation view of the contact member of FIG. 6, withan external wire connection;

FIG. 8 is an end view taken approximately along line 8--8 in FIG. 7,with the wire in cross section;

FIG. 9 is a side elevation view, on an enlarged scale of the terminalelement of a contact member constructed in accordance with anotherembodiment of the invention;

FIG. 10 is a front elevation view of the contact member of FIG. 9;

FIG. 11 is an end view taken approximately along line 11--11 in FIG. 10,with a part of the dielectric contact mount and a part of an externalconductor also illustrated;

FIG. 12 is an end view, similar to FIG. 11, illustrating a modificationin the construction of the terminal element of FIGS. 9-11;

FIG. 13 is an isometric view, on a reduced scale, of the contact memberterminal element of FIGS. 9-11;

FIG. 14 is a side elevation view of the terminal element of a contactmember constructed in accordance with another embodiment of theinvention;

FIG. 15 is a front elevation view of the terminal element illustrated inFIG. 14;

FIG. 16 is an isometric projection of the terminal element of FIGS. 14and 15;

FIG. 17 is a side elevation view of the terminal element for a contactmember constructed in accordance with an additional embodiment of theinvention;

FIG. 18 is a front elevation view of the terminal element illustrated inFIG. 17;

FIG. 19 is an orthagonal projection of the terminal element illustratedin FIGS. 17 and 18;

FIG. 20 is an orthagonal projection illustrating a limited modificationof the construction shown in FIGS. 17-19; and

FIG. 21 is a detail illustration of a part of the electrical connectorreceptacle shown in FIG. 3, taken approximately as indicated by line21--21 therein.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-5 illustrate the basic structure of an electrical connectorconstructed in accordance with one embodiment of the present invention.The electrical connector comprises a plug unit 30, shown in FIGS. 1, 2and 5, and a receptacle unit 40 illustrated in FIGS. 3, 4 and 5. Plugunit 30 includes a first contact mount 31 of molded dielectric materialhaving a plurality of individual contact mounting supports or passages32; passages 32 extend completely through mount 31, as best shown inFIG. 5. Plug unit 30 further includes a corresponding plurality ofcontact members 33, each of the contact members 33 being mounted in oneof the contact passages 32 (FIGS. 2 and 5). Each contact member 33, asshown in some detail in FIG. 5, includes an active contact element 34comprising a thin, flat, resilient metal element bent into a re-entranthook configuration at the end 35 to engage in a small retaining slot 36formed in mount 31 adjacent the inner end of passageway 32. Contactmember 33 further comprises an integral terminal element 37 which ispositioned in the outer end of the contact passage 32 which has an upperlongitudinal side open for receiving the insulation covered electricalconductor. Contact member 33 is held in contact passage 32 by retainerelements 38 and 39, element 39 constituting a tab that is bent up to aretaining position as shown in FIG. 5 after the contact member has beeninserted into passage 32.

The construction of receptacle unit 40 (FIGS. 3-5) is similar to butcomplementary to plug unit 30. Thus, receptacle 40 comprises a contactmount 41 of molded dielectric material having a plurality of contactpassages 42 corresponding in number and position to the contact passages32 in mounting block 31 and are arranged in two parallel rows 70 and 71as shown in FIGS. 3-4. In the illustrated connector, FIGS. 1-5, thereare fifty contacts in each of the connector halves 30 and 40; thisnumber may vary substantially, depending on the number of circuits to beinterconnected.

A unitary conductive sheet metal contact member 43 is mounted in eachcontact passage 42 of receptacle mount 41. Each contact member 43, asshown in FIG. 5, comprises a flat resilient active spring contact member44 bent over at its inner end 45 to fit into a small retaining slot 46in mounting block 41. The outer portion of contact member 43 comprises aterminal element 47. Each contact member 43 is held in position in itscontact passage 42 in mounting block 41 by means of appropriate retainerelements 48 and 49 (FIG. 5).

As thus far described, and as illustrated in FIGS. 1-5, the constructionof the connector comprising plug unit 30 and receptacle unit 40 isessentially similar to the multiple-contact electrical connectordescribed and illustrated in Yopp U.S. Pat. No. 3,002,176. Theindividual contact members 33 can be readily and rapidly mounted in theplug mounting block 31 by inserting the contact members in theindividual contact passages 32 and then bending each of the retainingtabs 39 outwardly to lock the contact members in place. The sametechnique is followed in assembling the contact members 43 in contactpassages 42 in the mount 41 of receptacle unit 40.

When the two connector units are joined, as by moving plug unit 31downwardly in the direction of arrow A in FIG. 5, the active contactelement 34 on each plug contact member 33 engages the active contactelement 44 of the corresponding contact member 43 in the receptacleunit. The yielding active contact elements of each mating pair ofcontact members afford dependable engagement and adequate contactpressures, without overflexing of either contact in the pair. Thespecific design shown for the contact elements allows the use of metals,in fabrication of the contact elements, of relatively low spring qualityand high electrical conductivity, affording a connector that is small insize yet adapted to normal voltages and currents used for datacommunication. The mating contact surfaces are maintained clean andbright and the connector joins with a snap-in action. In actualpractice, plug unit 30 and receptacle unit 40 are each usually providedwith a metal housing for increased strength and protection; the housingshave been omitted from the drawings because they are not critical to thepresent invention.

In the electrical connectors of the aforementioned Yopp patent, theterminal elements of the individual contact members are ofchannel-shaped configuration, and electrical connections to individualconductors are effected by conventional solder techniques. For thecontact members 33 and 43 of the present invention, however, solderingis not employed. That is, the unitary contact members 33 and 43, eachformed from a single piece of thin conductive sheet metal, includeprovision for solderless insulation-piercing connection to an insulatedelectrical conductor simply by insertion of the electrical conductorinto the terminal element of the contact member.

FIGS. 6, 7 and 8 illustrate, on a greatly enlarged scale, oneconstruction that may be employed, in accordance with the presentinvention, for the terminal element 47 formed at the outer end of eachof the contact members 43. It should be noted that, in thisspecification, the term "outer end," as applied to either a contactmember or a contact passage in the electrical connector, refers to theportion of the connector to which individual external electricalconductors are connected. It will be recognized that the configurationof the connector can be changed so that the terminal elements of thecontact members are not linear extensions of the active contactelements, without changing this relationship.

The outer end of contact member 43, comprising terminal element 47, asshown in FIGS. 6-8, comprises an elongated channel of U-shaped crosssectional configuration having a channel-forming walls illustrated bybottom wall 51 and side walls 52 and 53. The retainer tab 49 is formedintegrally with side wall 53. Tab 49 is shown in its initial position,bent over at approximately 90° to the top of side wall 53, this beingthe initial position of the tab when contact member 43 is inserted inthe dielectric mount 41. Once the contact is in place in the dielectricmount, tab 49 is bent outwardly to the retaining position shown in FIG.5.

Terminal element 47 of contact member 43 includes two terminal flanges54 and 55. Flange 54 is formed by two opposed transverse flange elements54A and 54B struck from side walls 52 and 53 respectively. The twoflange elements 54A and 54B are bent inwardly across the end of thechannel constituting terminal element 47, forming an upwardly openingnotch 56 (FIGS. 7 and 8). The upper portion of notch 56 has downwardlyconverging thin-edges walls 57A and 57B (FIG. 8) that afford a cuttingsection for shearing through the insulation on an insulated electricalconductor. The medial portion of notch 56 has gradually thickened edges,constituting a transition section 58, for spreading the insulation awayfrom a conductor inserted in the notch. The lower portion of notch 56has smooth, rounded edges along its walls that afford a terminal section59 constituting a pressure jaw that engages an electrical conductor inwiping contact.

The second terminal flange 55 of terminal element 47 (FIGS. 6 and 7) issimilar in construction to flange 54. It includes a first flange element55A struck from channel wall 52 (FIG. 7) and bent inwardly across thechannel. A second flange element 55B is struck from wall 3 and bentinwardly across the channel in alignment with flange element 55A. Bothof the flange elements are formed with sloping upper walls and are bentback upon each other to afford a cutting section, a transition section,and a terminal section as described for flange 54 (FIGS. 7 and 8).

To complete an electrical connection to terminal element 47, a metallicconductor 61 with an electrical insulation covering 62 is inserted intothe two notches in the terminal flanges 54 and 55 as generally indicatedin FIG. 7. As the insulated conductor is forced downwardly into thenotches in the two terminal flanges, the converging notch walls, such asthe walls 57A and 57B (FIG. 8), cut into the insulation on the conductorin a shearing action similar to that performed by conventionalinsulation-piercing terminal elements. As the conductor is forcedfurther downwardly beyond lower ends 60A and 60B of thin-edged walled57A and 57B hand into notch 56 in flange 54, it enters the transitionsection 58. As illustrated in FIG. 8, transition section 58 is disposedat the upper ends 68A and 68B or entrance to lower transition section 58and separates transition section 58 from the lower ends 60A and 60B ofthe thin flat cutting edges of walls 57A and 57B. The graduallythickened walls for the notch beginning at transition section 58, tendto spread the insulation. The lower folded portions of the notch walls,in the lower terminal section 59, engage the conductor 61 withoutcutting into it and apply a full normal force in sliding frictioncontact with the conductor. In FIG. 8, the final position of anelectrical conductor 61 with an insulating cover 62 is shown in notch 56of terminal flange 54, with the electrical connection completed and withinsulation 62 substantially disposed within the channel. The same actionoccurs at flange 55.

FIGS. 9-11 and 13 illustrate another embodiment of the presentinvention, comprising a terminal element 147 formed as an integral partof a unitary sheet metal contact member 143. Only the terminal elementis illustrated, the active contact element may correspond to the contactelement 44 of FIG. 5. Terminal element 147 is of elongatedchannel-shaped construction with a bottom wall 151 and side walls 152and 153. At the outer end of the terminal element, a portion of sidewall 152 is bent across the channel to afford a first terminal flange154. A second terminal flange 155 is struck from the other side wall 153and is bent inwardly to extend across the channel at a location spacedfrom the outer terminal flange 154.

Terminal flange 154 is provided with an upwardly opening notch 156 forreceiving an insulation covered electrical conductor such as theconductor 161 with its insulation 162 (FIG. 11). The upper portion ofnotch 156 includes the thin, downwardly converging notch walls 157A and157B. The thickness of walls 157A and 157B in the upper portion of notch156 is limited to the thickness of the sheet metal from which terminalelement 147 is formed, usually of the order of 0.005 inch and forms thinflat cutting surfaces 170A and 170B (FIG. 13) facing into the notch andextending across at least a major portion of the thickness of sheetmetal providing walls 157A and 157B. Thus, the upper portion of notch156 affords a cutting section for shearing through the insulation 162 onconductor 161.

The medial portion of notch 156 is bent away from the notch and iscoined or swedged to afford gradually thickened edges constituting atransition section 158. Transition section 158 spreads the insulation onconductor 161 as the conductor is progressively inserted into notch 156.The lower portion of notch 156 has smooth, thick edges affording aterminal section 159 having portions of multiple thickness formingthickened edges and constituting a pressure jaw that engages theelectrical conductor 61 in a smooth wiping friction contact that affordsa good electrical connection between conductor 161 and terminal flange154.

Terminal flange 155 is essentially similar to flange 154, as best shownin FIGS. 10 and 13. That is, the second terminal flange 155 isconstructed with a notch for receiving an insulation-covered electricalconductor, the upper portion of the notch having thin, downwardlyconverging edges that afford a cutting section and that merge into amedial portion of the notch having gradually thickened edges. The bottomportion of the notch in terminal 155, as in flange 154, has smooth,rounded, thickened edges that provide a terminal section constituting apressure jaw for engaging the electrical conductor in good electricalcontact.

In the construction illustrated in FIGS. 9-11 and 13, the end portion ofchannel wall 153 adjacent terminal flange 154 is bent inwardly andshaped to afford a slot 164. Similarly, a part of channel wall 152aligned with terminal flange 155 is deformed inwardly and pressed into aconfiguration that provides a vertically extending retainer slot 165. Interminal element 147, the free end of flange 154 engages in slot 164 tobrace the flange and prevent the flange from being bent out of positionwhen completing an electrical connection to a conductor inserted intothe flange. The retaining slot 165 in channel wall 152 serves the samepurpose, strenthening flange 155 mechanically and preventing deformationof the flange when an electrical conductor is inserted into terminal147.

Terminal element 147 also includes a retainer tab 166 that is formedintegrally with and that extends upwardly from the one side wall 152 ofthe channel. Retainer tab 166 remains in the illustrated position untila conductor has been inserted in terminal element 147 and electricalconnection has been established. Once this has been done, tab 166 can bebent over to engage the outer surface of the electrical conductor andhold the insulated conductor in the terminal element 147.

In the end view of FIG. 11, the side walls of notch 156, particularly inthe terminal section 159 of the notch, are shown as diverging slightly,with the bottom of the notch terminating in a rounded lower wall 167.Thus, the walls of the conductor-receiving notch 156 apply a limitedclamping force to conductor 161, holding the conductor in the notch andin electrical contact with terminal flange 154. With this construction,notch 156 is formed apart slightly as conductor 61 passes through thetransition section 158 and into the terminal section 159 of the notch.To prevent excessive distortion and assure effective operation ofterminal element 147 the overall width of terminal element 147 is madeonly slightly smaller than the spacing between the two walls 168 and 169defining this portion of the contact passage 42 in the molded dielectricmounting block 41 (FIG. 11). Thus, there is a close fit (0.001 inchtypical clearance) between the walls 168 and 169 of passage 42 andterminal element walls 152 and 153; this prevents undue spreading ofterminal element 147 when an insulated conductor is inserted in theterminal flange notches.

It is not essential that the walls of the terminal flange notches bemade divergent, in the terminal section, in the manner shown in FIG. 11.The notch walls may be maintained parallel throughout the transitionsection and the terminal section. This is particularly true when othermeans such as the retaining tab 166, are provided for holding theelectrical conductor in the terminal flanges. Thus, the walls of theterminal section may be made parallel to each other, as shown interminal section 159A, illustrated in FIG. 12.

FIGS. 14, 15 and 16 illustrate a terminal element 247, constructed inaccordance with another embodiment of the invention, and constituting anintegral part of a sheet metal contact member 243. The active contactelement of member 243 may have the same construction as discussed abovein connection with FIG. 5, and hence has not been illustrated. Terminalelement 247 is of U-shaped cross sectional configuration, forming anelongated channel having a bottom wall 251 and side walls 252 and 253.At the outer end of the channel, a first terminal flange 254 is struckfrom an extension of side wall 252 and is bent across the channel toform a first terminal flange 254. A second terminal flange 255 is struckfrom the other side wall 253 and is bent across the channel in spacedrelation to flange 254. Flange 254 includes an extension portion that isinserted into a retainer slot 264 in side wall 253, bracing the free endof flange 254 and thus affording a rigid construction for the flange.Similarly, an extension at the end of flange 255 projects into aretaining slot 265 cut into channel wall 252, affording a retainingstructure for the free end of flange 255 and thus providing a rigidmechanical construction.

The two flanges 254 and 255 in terminal element 247 are similar inconfiguration to the flanges 154 and 155 of terminal element 147 (FIGS.9-11 and 13). Thus, as shown in FIG. 16, flange 254 has aconductor-receiving notch 256 with thin, downwardly converging edges257A and 257B forming a cutting section for shearing through theinsulation on an insulated conductor inserted into slot 256. The cuttingsection of notch 256 merges with a transitional section 258 havinggradually thickened edges that serves to spread the insulation when aconductor is inserted in notch 256. The lower portion 259 of notch 256has thick rounded edges, terminating in a rounded lower wall, affordinga pressure jaw for gripping the conductor and completing an electricalconnection therewith when the insulated conductor is inserted in notch256. A corresponding construction is provided for an insulation-piercingelectrical connection notch formed in terminal flange 255. As before, aretainer tab 266 may be incorporated in terminal element 247. After anelectrical conductor has been inserted into terminal element 247, tab266 can be bent over to a position in which it extends across the openside of the channel and locks the conductor into the channel. Thenotches in terminal flanges 254 and 255 may have divergent walls intheir transition and terminal sections, as in FIG. 11, or may haveparallel walls in these sections, as in FIG. 12.

FIGS. 17, 18 and 18 illustrate yet another embodiment of the terminalelement of the present invention, comprising a terminal element 347formed integrally with and constituting a part of a one-piece sheetmetal contact member 343. Terminal element 347 is again of U-shapedchannel construction, including a bottom wall 351 and side walls 352 and353. A first terminal flange 354 is formed as a part of bottom wall 351and is bent upwardly so that the flange extends across the outer end ofthe channel. Similarly, a second terminal flange 355 is struck from thebottom wall 351 of the channel and is bent upwardly so that the flangeextends across a medial portion of the channel, spaced from flange 354.The ends of flange 354 are formed with individual projections thatengage in two slots 364A and 364B in the channel walls 352 and 353,respectively. Similarly, flange 355 has an extension on each end, andthese extensions are engaged in slots 365A and 365B in the side walls352 and 353, respectively. As will be apparent from FIG. 19, this formsa strong, rigid construction for the terminal flanges, preventingexcessive distortion when an electrical conductor is inserted interminal element 347.

Terminal flange 354 includes a notch 356 affording an effectiveinsulation-piercing terminal connection for an insulated wire insertedin the notch. The configuration for notch 356 is similar to the notchconstructions described above. Thus, the connection notch 356 in flange354 opens upwardly of the channel and has thin, downwardly convergingedges 357A and 357B forming a cutting section for piercing andpenetrating the insulation of a wire inserted in the notch. The cuttingsection merges with a transition section 358 with gradually thickeningedges that spread the insulation. The lower portion of notch 356 hassmooth, thickened walls, formed by swedging or coining the bent portionsof the flange, that constitute an effective pressure jaw connector 359that engages the conductor in firm sliding contact to afford a goodelectrical connection. A similar construction is used for aninsulation-piercing electrical connector notch formed in terminal flange355.

Th construction of terminal element 347 (FIGS. 17-19) may also bemodified to utilize retaining notches for the terminal flanges that areformed by bending the side walls 352, 353 rather than being cut into theside walls. This modification is illustrated in FIG. 20, as applied toterminal flanges 354. In the construction shown in FIG. 20, the endportion of side wall 352 is formed to afford a vertically extending slot364C. A similar vertical slot 364D is formed by bending an alignedportion of wall 353 in the same manner. This affords an alternate meansfor achieving the requisite mechanical rigidity and strength in theterminal flange construction to prevent excessive distortion when anelectrical connection is made. In the terminal element constructionsshown in FIGS. 17-20, a retaining tab 366 may again be provided to locka conductor in place once it is inserted in and electrically connectedto the terminal flanges.

In some instances, it may be desirable to eliminate the retainer tab onthe contact member (tabs 66, 166, 266 and 366) or to providesupplemental retainer means for the electrical conductors. FIG. 21,considered in conjunction with FIGS. 2 and 3, illustrates a conductorretainer structure that is incorporated in the receptacle unit 40 as apart of the dielectric contact mount 41 as another feature of theinvention.

As shown in FIGS. 3 and 21, mount 41 includes an integral molded barrier401 extending across the outer ends of all of the contact passages 42.Barrier or rear extension 401 includes a plurality of retainer grooves402, a groove 402 aligned with and communicating with the end of eachpassage 42. Each groove is arranged for receiving conductor blank 402includes a downwardly converging entrance section 403 leading into ashort, narrow retainer section 404 that in turn leads into a wideretainer section 405 slightly larger than the overall diameter of aconductor 61 and its insulator covering 62. Barrier 401 may also have aseries of slots 406 in the walls therein adjacent retainer grooves 402,facilitating flexing of the retainer groove walls.

When an insulated conductor is connected to one of the contact memberterminals, using the construction shown in FIG. 21, the conductor isforced down through entrance section 403 and retainer section 404 andinto receptacle section 405 of retainer groove 402. The final alignmentof the conductor 61 and insulator covering 62 is shown in FIG. 21;conductor 61 is gripped in the notch between flange elements 54A and 54Bas described above for FIGS. 6-8. In addition, after passing throughretainer section 404, the insulated conductor is firmly held in place inreceptacle 405. During insertion, the walls of groove 402 spread,particularly in section 404, then snap back into the illustratedretention position holding conductor 61 in longitudinal alignment withthe notch formed by flange elements 54A and 54B of terminal element 47.

In the foregoing description, the terminal elements for contact membersused in the receptacle unit 40 have been described in detail. Thecontact members for plug unit 30 can be constructed in the same manner,using any of the configurations shown in FIGS. 6 through 20, and theplug unit contact mount 31 can be molded to afford the same kind ofresilient retention means as shown in FIG. 21. In both connector units,the terminal elements of the invention provide for rapid solderlessconnection of external conductors, minimizing or eliminating the scoringof conductors present in other insulation-piercing connections andproviding sliding friction contact at adequate pressure levels. Theterminal elements can be used, even in miniaturized connectors, atvoltages of several hundred volts, and can carry several amperes ofcurrent. The conductors are held firmly in the terminal elements, bytheir retainer tabs, by the retainer grooves in the contact mounts, bythe terminal flange jaws, or by a combination thereof. The contactmembers of the invention can be used in two-unit connectors, asdescribed in conjunction with FIGS. 1-5; a single connector unit,incorporating the advantageous features of the invention, can also beused with a mating connector unit of different construction. Thus, thereceptacle unit 40 can be employed, with little or no modification, inmaking circuit connections to a mating connector comprising a part of aprinted circuit board.

I claim:
 1. A unitary contact member formed from a single piece of thin,conductive sheet metal, comprising:an active contact element; and anintegral terminal element, comprising side and bottom walls forming anelongated channel of U-shaped cross-sectional configuration with innerand outer end portions, said terminal element including at least oneterminal flange, formed by at least one flange element struck from oneof said walls of said channel and bent to extend transversely of saidchannel, said flange extending completely across said channel andinterlocked with at least one other wall of said channel, said flangehaving an upwardly open notch for receiving an insulation-coveredelectrical conductor, the upper portion of said notch convergingdownwardly and having thin edges to afford a cutting section forshearing through the insulation on the conductor, the medial portion ofsaid notch having gradually thickened edges constituting a transitionsection for spreading the insulation on the conductor, and the lowerportion of said notch having smooth, curved thickened edges affording aterminal section with a resilient pressure jaw engaging the electricalconductor in wiping contact.
 2. A unitary contact member, according toclaim 1, in which said terminal element includes two of said terminalflanges and inner and outer end portions, one terminal flange beinglocated adjacent the outer end portion of said terminal element and theother terminal flange being located adjacent the inner end portion ofsaid terminal element, each terminal flange having a conductor-receivingnotch affording said cutting, transition, and terminal sections.
 3. Aunitary contact member, according to claim 1 in which said terminalflange is struck from one of said side walls of said channel, extendscompletely across said channel, and projects into a retaining slot inthe other side wall of said channel.
 4. A unitary contact member,according to claim 1, in which said terminal flange is struck from thebottom wall of said channel and projects into retaining slots in bothside walls of said channel.
 5. A unitary contact member, formed from asingle piece of thin, conductive sheet metal, comprising:an activecontact element; and an integral terminal element, comprising side andbottom walls forming an elongated channel of U-shaped crosssectionalconfiguration with inner and outer end portions; said terminal elementincluding at least one terminal flange, formed by at least one flangeelement struck from one of said walls of said channel and bent to extendtransversely of said channel, said flange having an upwardly open notchfor receiving an insulation-covered electrical conductor, the upperportion of said notch converging downwardly and having thin edges toafford a cutting section for shearing through the insulation on theconductor, the medial portion of said notch having gradually thickenededges constituting a transition section for spreading the insulation onthe conductor, and the lower portion of said notch having smooth, curvedthickened edges affording a terminal section with a resilient pressurejaw engaging the electrical conductor in wiping contact, said transitionand terminal sections of each terminal flange notch being formed byflaps folded away from the center of the notch and coined or swedgedinto the recited shape at said transition section.
 6. A unitary contactmember, according to claim 5, in which the terminal section of saidterminal flange notch has downwardly diverging walls which are spreadduring insertion of an electrical conductor and which apply a retainingforce to hold the conductor in said notch.
 7. A unitary contact memberaccording to claim 5, in which the side walls of the terminal section ofsaid terminal flange notch terminate in a smooth, arcuate bottom wall.8. A unitary contact member, formed from a single piece of thin,conductive sheet metal, for an electrical connector of the kindcomprising a first dielectric contact mount and a second dielectriccontact mount having a plurality of contact mounting passages, the twocontact mounts fitting together to align the inner ends of the contactpassages in the first mount one-for-one with the inner ends of thecontact passages in the second mount, said contact member comprising:anactive contact element for positioning in the inner end of a givenpassage in one mount and for engaging a mating active contact elementpositioned in the inner end of the aligned passage in the other mount;and an integral terminal element, comprising an elongated channel ofU-shaped cross-sectional configuration for positioning in the outer endof said given passage, said terminal element including at least oneintegral terminal flange struck from one wall of said channel, saidflange extending completely across said channel, and being interlockedwith at least one other wall of said channel, said flange having anupwardly opening notch for receiving an insulation-covered electricalconductor, said notch having a upper portion converging downwardly andhaving thin edges to afford a cutting section for shearing through theinsulation on the conductor, a medial portion of said notch havinggradually thickened edges constituting a transition section forspreading the insulation on the conductor, and a lower portion of saidnotch having smooth, thickened edges affording a terminal section with aresilient pressure jaw engaging an electrical conductor in wipingcontact.
 9. A contact member for interconnection to aninsulation-covered electrical conductor, comprisinga longitudinallyextending terminal element formed of thin, conductive sheet metal withat least one pair of opposed, transverse flange elements forming anupwardly open notch for receiving said conductor, said notch includingan upper portion having thin flat edges converging downwardly to affordan insulation cutting section with said thin flat edges extending acrossat least a major portion of a thickness of said sheet metal, a lowerportion having smooth, curved, thickened edges to afford a conductorengaging terminal section, and an insulation-spreading medial portionbetween said upper and lower portions with edges having a thicknessgreater than the thickness of said thin edges, said flange elementincluding portions of multiple thicknesses of said sheet metal, saidthin sheet metal being bent to form said thickened edges, and saidthickened edges being resiliently spread during insertion of theelectrical conductor and bearing against the conductor in pressureengagement.
 10. A contact member according to claim 9 including anactive element for connection to a circuit element and in which saidterminal element includes a pair of said notches with said notches beinglongitudinally displaced and having upper ends forming an entrance tosaid lower portion, and an insulation-spreading medial portion betweensaid upper and lower portions with edges having a thickness greater thanthe thickness of said thin edges and extending to said upper ends ofsaid lower portions.
 11. A contact member according to claim 9 in whichsaid terminal element includes walls forming a channel open to receivesaid conductor, with at least one of said walls integrally supportingsaid flange elements.
 12. A contact member for interconnection to aninsulation-covered metallic conductor, comprising,a longitudinallyextending terminal element formed of thin, conductive sheet metal withat least one pair of opposed, transverse flange elements forming anupwardly open notch for receiving said conductor, said notch includingan upper portion having thin edges converging downwardly to afford aninsulation cutting section and a lower portion having smooth, curved,thickened edges to afford a conductor engaging terminal section, saidflange elements including portions of multiple thicknesses of such sheetmetal forming thickened edges, said thickened edges being downwardlydiverging and being spread during insertion of said conductor to apply aretaining force to hold the conductor in said notch.
 13. An electricalconnector unit comprising: insulating means including a plurality ofparallel longitudinally extending passages with inner and outer endportions each outer end portion having an upper longitudinal side openfor receiving an insulation-covered electrical conductor, anda pluralityof contact members mounted in said passages, including terminal elementsdisposed in said outer end portions, each of said terminal elementsincluding at least one pair of opposed, transverse flange elementsforming an upwardly opening notch for receiving said conductor, saidnotch including an upper portion having thin edges converging downwardlyto afford an insulation cutting section and a lower portion havingsmooth, curved thickened edges to afford a conductor engaging terminalsection, said flange elements being formed of thin, conductive sheetmetal and including portions of multiple thicknesses of said sheet metalforming said thickened edges.
 14. An electrical connector unit,according to claim 13, in which said insulating means includes:conductorretention means including a dielectric extension disposed across theouter end portions of said contact passages, said extension including aplurality of longitudinally elongated conductor support surfacesindividually aligned with individual outer end portions and means forreleasably retaining the individual conductors extending longitudinallyaway from the passages from upward movement in a direction out of thelower terminal sections of the notches.
 15. An electrical connectorunit, according to claim 14, in which said end extension includes aplurality of elongated retainer grooves, one for each contact passage,each retainer groove including a wide entrance section leading to anarrow retainer section which in turns leads to a substantially widerreceptacle section large enough to accommodate an insulation-coveredconductor.
 16. An electrical connector unit, according to claim 14,wherein said outer end portion of each of said passages is of elongatedU-shaped configuration with side walls and said terminal elementincludes an elongated channel with said flange elements and side andbottom walls, the side walls of the terminal element affording a closefit with the side walls of the outer end of the contact passage in whichthe contact member is mounted, so that the insulating means preventsexcessive distortion of each terminal element when a conductor isinserted in the terminal flange notch thereof.
 17. An electricalconnector unit, according to claim 14, in which each terminal flange isstruck from one wall of said terminal element channel and bent inwardlyacross said channel into interlocking relation with at least oneadditional wall thereof.
 18. An electrical connector unit according toclaim 13 in which said contact members include active elements forconnection to circuit elements and said notch includes aninsulation-spreading medial portion between said upper and lowerportions.
 19. An electrical connector unit according to claim 13 inwhich said terminal elements include channel-forming walls of said sheetmetal with at least one of said walls being integral with at least oneof said flange elements, and in close fit with said insulating means toprevent excessive distortion of said terminal flange elements when saidconductor is inserted in the notch thereof.
 20. An electrical connectorunit according to claim 19 in which said insulation of said conductor issubstantially disposed within said channel.
 21. An electrical connectorunit according to claim 19 in which said contact members include activeelements disposed in said inner end portions, said terminal elementseach include a pair of said notches, even including aninsulation-spreading medial portion between said upper and lowerportions.
 22. An electrical connector unit according to claim 13 inwhich said terminal element includes channel forming side walls withsaid pair of flange elements being disposed between said walls andintegral therewith. .Iadd.
 23. An electrical contact member including alongitudinally extending terminal element formed of conductive sheetmetal with at least one pair of opposed transversely disposed flangeelements and an upwardly opening, insulation-spreading notch with adownwardly converging portion and formed by said flange elements forreceiving an insulation-covered metallic conductor inserted downwardlyinto the notch, the notch including an upwardly disposed portion forspreading the insulation on the conductor and a lower portion withwiping surfaces for electrically engaging the conductor, said lowerportion being constructed of said sheet metal bent to form smooth,thickened surfaces as said wiping surfaces for engaging said conductor..Iaddend. .Iadd.
 24. The contact member of claim 23, wherein said notchfurther includes a coined or swedged medial portion having graduallythickened edges constituting a transition section between said upper andlower portions. .Iaddend. .Iadd.
 25. The contact member of claim 23wherein said terminal element includes at least one wall and said flangeelement includes a portion bent from said wall with an additional bendto form said thickened surface along said additional bend..Iaddend..Iadd.
 26. The contact member of claim 25 including saidconductor disposed in said notch, said wiping surfaces extending throughsaid insulation and providing a pressure jaw engaging said metallicconductor. .Iaddend..Iadd.
 27. The contact member of claim 26 whereinsaid terminal element is constructed of said sheet metal and includestwo opposed, longitudinally extending channel walls and two pairs ofsaid flange elements with each of said pairs being separatedlongitudinally and each flange element being carried by one of saidwalls. .Iaddend. .Iadd.
 28. The contact member of claim 26 wherein atleast one of said walls includes a conductor retaining tab integrallyjoined to one of said walls for retaining said conductor from upwardmovement in said terminal element. .Iaddend. .Iadd.
 29. The structure ofclaim 26 wherein the said curved surfaces comprise said sheet metalfolded upon itself. .Iaddend. .Iadd.
 30. An electrical connectorincluding insulating means with a plurality of parallel,longitudinally-extending passages with upwardly open portions and aplurality of contact members comprising terminal elements includingchannel walls of conductive sheet metal each formed with pairs ofopposed flange elements and upwardly opening, insulation-piercingnotches formed by said flange elements disposed in said passages forreceiving insulation-covered metallic conductors, the notches includingupwardly disposed portions for spreading the insulation on theconductors and lower portions with wiping surfaces for electricallyengaging the conductors, said lower portions being constructed of saidsheet metal bent to form smooth, thickened surfaces providing saidwiping surfaces for engaging said conductors. .Iaddend..Iadd.
 31. Theconnector of claim 30 wherein said sheet metal is formed in a reverseband with at least two thicknesses of said sheet metal forming saidsmooth, thickened surfaces along a longitudinal portion of saidconductors. .Iaddend..Iadd.
 32. The connector of claim 31 including aplurality of said conductors disposed in said notches with said wipingsurfaces extending through said insulation and providing pressure jawsengaging said metallic conductors. .Iaddend. .Iadd.
 33. An electricalcontact member including a longitudinally-extending terminal elementformed of conductive sheet metal with at least one pair of opposed andtransversely disposed flange elements and an upwardly opening notchformed by said flange elements for receiving an insulation-coveredmetallic conductor inserted transversely of its longitudinal axisdownwardly into the notch, the notch including a lower portion withwiping surfaces for electrically engaging the conductor, said lowerportion being constructed of said sheet metal bent to form smooth,thickened surfaces providing said wiping surfaces for engaging saidconductor. .Iaddend..Iadd.
 34. The contact member of claim 33 whereinsaid terminal element includes at least one wall and said flange elementincludes a portion bent from said wall with an additional bend to formsaid thickened surface along said additional bend. .Iaddend..Iadd. 35.The contact member of claim 34 including said conductor disposed in saidnotch, said wiping surfaces extending through said insulation andproviding a pressure jaw engaging said metallic conductor..Iaddend..Iadd.
 36. In combination, an electrical contact membercomprising a terminal element constructed of conductive sheet metalincluding a pair of transversely disposed and opposed pressure jawsprojecting inwardly between said walls and an upwardly opening notchformed by said jaws with a portion including upwardly-extending smooth,thickened wiping surfaces, said sheet metal being bent to form saidsurfaces, and an insulation-covered metallic conductor disposedlongitudinally in said notch, said surfaces including portions extendingthrough said insulation and engaging said conductor. .Iaddend..Iadd. 37.The combination of claim 36 wherein each of said pressure jaws include afirst bend of said sheet metal joined to one of said walls and a secondbend providing one of said smooth, thickened wiping surfaces..Iaddend..Iadd.
 38. An electrical contact terminal element formed ofconductive sheet metal to provide a longitudinal channel with at leastone pair of opposed transversely disposed flange elements integraltherewith forming an upwardly open notch for receiving a conductor ofgreater width than the width of said notch inserted downwardly into thenotch by movement of said conductor transversely of its own longitudinalaxis, the flange elements each including a portion with a wiping surfacefor electrically engaging and maintaining engagement with the conductor,said flange elements being deformed from said sheet metal to provide asmooth curved surface having an axis of curvature transverse to thelongitudinal axis of the conductor and providing said wiping surface..Iaddend..Iadd.
 39. The structure of claim 38 wherein said sheet metalhas a thickness substantially thinner than the notch with respect tosaid longitudinal axis of said conductor. .Iaddend. .Iadd.
 40. Thestructure of claim 38 wherein said curved surface comprise the sidewalls of the channel deformed inwardly. .Iaddend..Iadd.
 41. Incombination, an electrical contact terminal element formed of conductivesheet metal to provide a longitudinal channel with at least one pair ofopposed transversely disposed pressure jaws integral therewith andhaving opposed conductor engaging wiping surfaces forming a notch; andan insulated metallic conductor with exposed metallic portionsintermediate insulated portions thereof maintained in pressureengagement with said wiping surfaces in said notch, said pressure jawseach being deformed from said sheet metal to provide a smooth curvedsurface having an axis of curvature transverse to the longitudinal axisof the conductor for engaging said conductor and providing said wipingsurface. .Iaddend.